The invention relates to a method for interconnecting electrical conduits in an underground borehole and to an electrical submersible pump (ESP) system that may be connected to electrical power supply conduits at a downhole location by means of the method.
It is known from International patent application wO 01/02699 to provide a wireline retrievable electrical submersible pump (ESP) system with a wet mateable electrical connector which permits retrieval of the ESP system and associated electrical motor to surface for maintenance, inspection or replacement, without the need to simultaneously pull the electrical power supply cable to surface, which is often damaged during such retrieval and then needs to be replaced by a new cable. The wet mateable electrical connector known from this prior art reference comprises axially spaced pairs of electrical contact rings that are concentric in the wellbore, does, after retrieval of the ESP system, not permit access to the wellbore beneath and is vulnerable to fouling by wellbore solids debris, that are to be flushed from an annular space between the connector parts in which the electrical contact rings are arranged when they are joined.
GB 2295409 describes a known method for interconnecting electrical conduits. In the known method a static pin connector part is arranged co-axially in a well and a moveable box connector part is landed on top of the pin connector part such that debris can be discharged into the borehole. U.S. Pat. No. 5,132,624 discloses a downhole electrical connector with a central throughbore to permit passage of debris.
It is an object of the present invention to provide a wet mateable electrical connector, which is less prone to accumulation of debris and does not require flushing of debris from a space between the connector parts.
It is a further object of the present invention to provide a wet mateable-electrical connector, which comprises a static part and a moveable connector part, which is connectable to an ESP system, and of which the static connector part can be configured such that it permits access to the wellbore beneath the connector after retrieval of the ESP system and associated moveable connector part.